It is now common practice to produce doors from sheet metal as replacements or for new construction. When these doors are to be used as outside entrances, as distinguished from interior doors, it is desirable to have one or more window sections, referred to as lights, formed in the door, and several prior patents involve providing a light in a metal door including the following U.S. Pat. Nos.:
______________________________________ 3,004,641 Johnson 3,487,602 Braun et al. 3,641,721 Martin 3,760,543 McAllister 3,969,857 Stark 4,128,977 Schubeis ______________________________________
While these patents appear to provide usable structures, they do not, with one exception, disclose structures which can be used to form a light in which the frame is recessed so that it does not protrude beyond or overlap the major outer door surfaces. In the one exception, Johnson, the techniques for holding the frame in place involve spot welding steps following the assembly of the door itself or involve frame strips which are held only by friction and are therefore not sufficiently secure to be usable in an outside door.
For completeness, reference is also made to U.S. Pat. Nos.:
______________________________________ 3,949,526 Sherlock et al. 4,024,691 Hanson et al. ______________________________________
which show, respectively, a corner brace used with extruded plastic tubular members for forming a door frame, and interlocking corner braces used with tubular metal extruded members, also to form a door frame.